Press for forming articles from plastic materials.



No. 635,026. Patented out. l7, I899.

w. E. SAUNDERS.-

PRESS FOR FORMING ARTICLES FROM PLASTI'C MATERIALS.

(Application filed Feb. 2'? 1899.) (No Model.) 2 Sheets-Sheet},

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No. 635,026. Patented Oct. l7, I899. W. E. SAUNDERS.

PRESS FOR FORMING ARTICLES FROM PLASTIC MATERIALS.

(Application filed Feb. 27, 1399. (No Model.) 2 Sheets-Sheet 2.

WILLIAM EDWARD SAUNDERS, or oLEvnLAND, OHIO.

PRESS FOR FORMING ARTICLES FROM PLASTIC MATERIALS.

' sPEcIFIoATIoN formin part of Letters Patent No. 635,026, dated. October 17, 1899. Application filed February 27,1899. rial No. 706,923. (N model" My invention relates to improvements inpresses for forming articles from plastic materials; and it consists in an improved construction, combination, and arrangement of the die-head and die, the object of the invention being to secure increased efficiency of the apparatus.

1n the drawings, Figure 1 represents in side elevation the die-head and cylinder of a forming-press with the die in place as in operation. Fig. 2 is a like view in-elevation of the same parts with the die removed. Fig. 3 is a central vertical section of the parts shown in Fig. 1. Fig. a is a front elevation showing the die drawn out for charging the cylinder. Figs. 5 and 6 are perspective views of the die, showing, respectively, the front and rear sides; and Fig. 7 is a side view in elevation of the same parts shown in Fig. 2, exhibiting a modification of the construction.

.A represents the press-cylinder, in which the plastic material is placed; B, the plunger fitting the cylinder and which when driven forward forces the plastic material out through the die 0.

D Dare heavy stay-rods which by means of nuts 01 cl'or equivalent means support the thrust-plate E against the heavy pressure of the press.

The front part ct of cylinder A is cut away to afford the die-seat f, as shown in Fig. 2, or space for the die is left between the front end of cylinder A and the plate E, as shown in Fig. 7, these parts constituting the die-head. The die when in place is forced firmly against the front of cylinder A by wedges g g, driven in wedge-seats h h, formed in therear side of the thrust-plate E, which forms the front'side of the die-seat. In the front end of the chamber a of cylinder A is formed a recess '6, (shown in Fig. 7 and indotted lines in Figs. 1 and 2,)

A stop 70 at the back of die-seat f snfficient throw to passbeyond chamber a i and project slightly into the chamber of die C, the result of which is that every particle of the material is forced out of the cylinder,

and when the plunger is retracted and the die removed the interior of cylinder A is empty and clean, no remnants of the charge of material being left therein, as is usually the case.

When the die is in place and the wedges g driven home, the cylinder, die, and plate E are practically a solid structure, and the en tire strain of the very .heavy pressure on plunger B is transmitted to and sustained by the stay-rodsD D.

The die 0 has on its front side a projection Z, in which the cavity 0 of the die is contracted to the size and form of the finished article and from which the plastic material is forced in its completed form as a continuous mass, which is cut-into suitable lengthsin any common and usual manner. To admit the projection Z, the plate E is cut away on the side from which the die is inserted, as shown in- Fig. l, and to support the die when drawn out a table or bracket m is affixed to the diehead, its top being exactly level with the bot tom of the die-seat f, as shown. When the die is drawn out of its seat, as in Fig. i, the cylinder is filled with previously-formed plugs of the plastic material. The die is then slid back into its seat against the stop 7t, the wedges g are driven into their seats, and the press is ready for operation. \Vhen the plunger has completed its travel, the wedges are driven out, the die is forced forward and drawn out, the plunger retracted, the cylinder refilled,and the operation again proceeded with.

To prevent the plastic material chilling or V hardening in the cylinder A, the latter is provided with a steam jacket o, to which inletpipe and outlet-pipe 0 are connected. For

the pressure; but as a positive precaution against their accidental displacement I prefer to provide holes 4" (see Fig. 4) in the plate E and to insert pinssthereimwhich abut against the ends of the wedges and prevent their moving in their seats. \Vhen the wedges are to be removed, the pins are easily driven out of the holes 7", and the wedges can then easilybe driven out to release the die.

Heret-ofore the dies of presses of this class have been secured in the die-head by means of screws or threaded parts, and the enormous pressure used, amounting sometimes to many tons, causes the threaded parts to be so tightly jammed that very great difficulty has been found in releasing the die, and great power, as well as much time, is required in effecting it. By my above-described device threaded parts are obviated, time is saved, .and the wedges are always easily removed, as the force applied to drive them out acts in the same direction as the resultant of the pressure exerted on them by the die.

For the purpose of strengthening the plate E on the side where it is recessed to receive the projection Z of die 0, should it be deemed necessary, a bridge T may be made to connect the parts of plate E above and below the opening through which the projection Z passes, as shown in Fig. 7, being extended sufficiently to allow the projection Z to pass through. This will prevent any,possible tendency of the heavy pressure to distort the plate E on the sidewhere it is cut away.

By the terms front and forward as used in the foregoing specification I mean the side or direction which faces in the same direction as the material moves in passing through the die, and by the terms back and rear is meant exactly the reverse.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In a press for forming articles from plastic materials, the combination of a cylinder havinga die-seat at its forward end, a thrustplate closing the front side of said die-seat, a die fitting in said seat, and wedges adapted to be driven between the die and thrust-plate for forcing the die into rigid engagement with the cylinder, substantially as described.

2. In apress for forming articles from plastic materials, the combinationof a cylinder having a die-seat at its forward end, a thrustplateclosing-the frontiside of said die-seat, and having wedge-seats cut in its rear face, a die fitting in said seat, and wedges adapted to be driven between the die and thrustplate forforcing the die into rigid engagement with the cylinder, substantially as described.

3. In a press for forming articles from plastic materials, the combination. of a steamheated cylinder having a die-seat at its forward end, a thrust-plate closingthe front side .of said die-seat, a die fitting in said seat, and

wedges adapted to be driven between the die and thrust-plate for forcing the die into rigid engagement with the cylinder, substantially as described.

4C. In a press for forming articles from plastic materials, the combination of a steamheated cylinder having a die-seat at its forward end, a thrust-plate closing the front side of said die-seat, a steam-heated die fitting in said seat, and wedges adapted to be driven between the die and thrust-plate for forcing the die into rigid engagement with the cylinder, substantially as described.

5. In a press for formingarticles from plastic materials, the combination of a steamheated cylinder having a die-seat at its forward end, a thrust-plate closing the front side of said die-seat, and having wedge-seats cut in its rear face, a die fitting in said seat, and wedges adapted to be driven between the die and thrust-plate for forcing the die into rigid engagement with the cylinder, substantially as described.

6. In a press for forming articles from plastic materials, the combination of a steamheated cylinder having a die-seat at its for ward end, athrust-plate closing the front side of said die-seat and having wedge-seats cutin its rear face, a steam-heated die fitting in said seat, and wedges adapted to be driven between the die and thrust-plate for forcing the die into rigid engagement with the cyl inder, substantially as described.

7. In a press for forming articles from plastic materials, the combination of a cylinder recessed at its front end and having a dieseat at its forward end, a thrust-plate closing the front side of said die-seat, a die fitting in said seat and having a projection on its rear side which fits the recess in the cylinder, and wedges adapted to be driven between the die and thrust-plate for forcing the die rigidly against the cylinder with said recess and projection in' engagement, substantially as described.

8. In a press for forming articles from plastic materials, the combination of a cylinder recessed at its front end and having a dieseat at its forward end, a thrust-plate closing the front side of said die-seat and having wedge-seats cut in its rear face, a die fitting in said seat and having a projection on its rear side which fits the recess in the cylinder, and wedges fitting said seats and adapted to be driven. between the'die and thrust-plate for forcing the die rigidly against the cylinder with said recess and projection in en gagement, substantially as described.

9. In a press for forming articles from plastic materials, the combination of a steamheated cylinder recessed at its front end and having a die-seat at its forward end, a thrustplate closing the front side of said die-seat, a steam-heated die fitting in said seat and having a projection on its rear side which fits the and having wedge=seats cut' in its rear face,

a steam-heated die fitting in said seat and having a projection on its rear side which fits the recess in the cylinder, and wedges fitting said seats and adapted to be driven between the die and thrustplate for forcing the die rigidly against the cylinder with said recess and projection in engagement, substantially as described.

11. The combination of a press-cylinder having a die-seat at its forward end, a die titting said seat and having a forward projec-" tion, a thrust-plate closing the front side of said die-seat and cut away to receive the forward projection of the die,and wedges adapted to be driven between the die and thrustplate for forcing the die into rigid engagement with 5 the cylinder, substantially as described.

12. The combination of a press-cylinder recessed at the front end of its chamber and having a die-seat at its forward end, a die fitting said seat and having on its rear side a projection fitting the recess of the cy1inder= chamber and on its front side a forward proof said die-seat and cut away to receive the forward projection of the die, and wedges adapted to be driven between the die and Thrust-plate for forcing the die into rigid 'en gagement with the cylinder, substantially as described.

13. In combination with the cylinder, die and thrust-plate of a press, the wedges for retaining the die'and cylinder in engagement, and removable stops for preventing the loosening of the wedges While under strain, substantially as described. v

14. The combination in a press of a cylinder having a die-seat at its forward end, a die fitting in said seat and having a forward-em tending projection on its front side, a thrust- 'jection, a thrust-plate closing the front side plate closing the front side of the die-seat and cut away to receive the projection of the die, wedges adapted to be driven between the die and thrust-plate for forcing the die into rigid engagement with the cylinder, and a bridgepiece spanning the opening in the thrust- 

